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Title: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: Jim Ratto on June 11, 2009, 19:17:32 pm Something to think about. How come lashcaps and rocker skuffer tips live but cams go flat? Seems like lubrication @ lash caps would be worse than the cam to lifter contact?
And the heat on a exhaust valve lashcap? Gotta be more extreme than cam lobe.... right? Somebody? Jim Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: DKK Ted on June 11, 2009, 19:38:16 pm I'm assuming that lash caps are heat treated to a higher rockwell that a cam is. Maybe somebody can rockwell a lash cap and a cam to see the difference.
Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: Steve DKK on June 11, 2009, 22:19:02 pm Cams and lifters are made from cast ductile iron and are not heat treated. Iron typically has good wear properties and the dome on the lifter carries a film of oil so they never (in theroy) come in contact. When we get into bigger spring pressures and steep ramps the film somtimes does not hold up. And when lobes / lifters start to wear they go fast.
Yes Lash caps and adjusters screws / feet are hardeded alloy steel. Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: Udo on June 11, 2009, 23:03:50 pm Cams and lifters are made from cast ductile iron and are not heat treated. Iron typically has good wear properties and the dome on the lifter carries a film of oil so they never (in theroy) come in contact. When we get into bigger spring pressures and steep ramps the film somtimes does not hold up. And when lobes / lifters start to wear they go fast. Yes Lash caps and adjusters screws / feet are hardeded alloy steel. Not all lifters are made of cast ductile iron ;) Udo Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: DKK Ted on June 11, 2009, 23:18:29 pm That may be true to a point, but most cams are cast ductile iron, yes there is steel billet, hard weld cams and other exotic matrials out there, but more $$$. I think Steve is talking in general on what cam are made of.
Ted Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: Steve DKK on June 11, 2009, 23:30:35 pm Yea I'm talking about the 99.8%. There are aways exceptions.
Ted, Thanks for having my back. Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: Ohio Tom (DdK) on June 12, 2009, 03:45:06 am Don't forget that the cam lobes are spinning at high rpm against the face of the lifter.
A rocker tip is only rocking back and forth on the lashcap/valve stem. It might move .100" . Less if they are setup properly. BTW.. Pauter rockers are awsome for this reason. Roller tips don't wear the valve stems. Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: stealth67vw on June 12, 2009, 03:52:05 am I've seen tons of old Autocrap and Sig Erson cheapie rockers pit and start to go "flat" on the wipers.
Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: Udo on June 12, 2009, 06:37:47 am That may be true to a point, but most cams are cast ductile iron, yes there is steel billet, hard weld cams and other exotic matrials out there, but more $$$. I think Steve is talking in general on what cam are made of. Ted There are no problems with cast ductile iron cams , only the lifters are not strong enough . This is why i manufacture those lifters udo Title: Re: if cams go flat, how come skuffer rocker tips and lash caps live? Post by: DKK Ted on June 12, 2009, 07:04:55 am Hi Udo, I agree with what your saying. For a long time, there has been alot of talk about the lifter problem, as you know, and I myself, I think I'm still taking chances with the lifters I'm using. I wish your lifters would be marketed here in the states more than what they are, and used more here also, to prove that they do work. And if they are, they need more exposer.
Ted |